Hydroxylation of aromatic compounds

ABSTRACT

Nuclear hydroxylation of aromatic compounds is effected by treating an aromatic compound with hydrogen peroxide in the presence of a catalyst comprising a metal derivative of a phthalocyanine at hydroxylation conditions.

United States Patent Massie 1451 Sept. 19, 1972 [54] HYDROXYLATION OFAROMATIC [56] References Cited COMPOUNDS UNITED STATES PATENTS 721 tzSthN.Massi30A1 l 1 3353 mines 3,407,237 10/1968 ves61 ..260/621 3,461,1708/1969 Schmerling ..260/613 [22] F11ed: Feb. 12, 1971 3,481,989 12/1969Vesely ..260/613 3,580,956 5/1971 Bloch ..260/621 1 3,600,446 8/1971M88816 ..260/621 Rented us. Appucauon Data 3,600,447 8/1971 Vesely..260/621 [63] Continuation-impart of Ser. No. 789,383, Jan. primmy E Bd H Ifi 1969, abandoned- Attorney-James R. Hoatson, Jr. and Raymond H.

Nelson [52] US Cl. ..260/613 D, 260/621 G, 260/622 R,

260/623 R, 260/624 R, 260/625, 260/621 K, [57] ABSTRACT 260,620 Nuclearhydroxylation of aromatic compounds is cf- [51] In. C C67: 37/00 fectedby treating an aromatic compound with hydrogen peroxide in the presenceof a catalyst com [58] Fleld ofSearch ..260/621G,613 D, t 1 d f hth l t622R 623R 260/624R 625 621K 620 pr1s1ng a mea e r1va1ve 0 a p aocyanme a6 R l 9 hydroxylauon condltlons.

1 1 Claims, No Drawings HYDROXYLATION OF AROMATIC COMPOUNDS CROSSREFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of my copending application Ser. No. 789,383, filedJan. 6,

- 1969 and now abandoned.

This invention relates to a process for the nuclear hydroxylation ofaromatic compounds. More particularly the invention is concerned with aprocess whereby one or more hydroxyl groups are introduced into thenucleus of an aromatic compound.

Hydroxylated aromatic compounds will find a wide variety of uses in thechemical field. For example, hydroquinone is an important chemical whichis utilized for photographic developers, in dye intermediates, inmedicine, as an antioxidant for fats and oils, as an inhibitor, incoating compounds, in paints and varnishes, as well as in motor fuelsand oils. In addition, it is also used as an intermediate for preparingmonoand dibenzyl ethers of hydroquinone, the latter compounds being usedas stabilizers, antioxidants, solvents, as well as being used inperfumes, plastics and pharmaceuticalsfLikewise, the dihydroxylatedbenzene compound, catechol, may be used as an antiseptic, inphotography,

dye-stuffs, as an antioxidant or light stabilizer. Furthermore, catecholis used as an intermediate for the preparation of the dimethyl ether ofcatechol which is used as an antioxidant and for the preparation of themono-methyl ether of catechol which is guaiacol, said guaiacol being animportant component of many medicinal preparations.

Likewise, phenol and the cresols are used in phenolic resins, asdisinfectants, flotation agents, surfactants, scouring compounds, lubeoil additives, photographic developers, intermediates in ink, paint, andvarnish removers, etc. In addition, hydroxy-substituted aromaticcarbohydrate derivatives may be used as intermediates in detergents,water-soluble pharmaceuticals, explosives, gelling agents, surfacecoatings, resins and oxidative inhibitors.

It is therefore an object of this invention to provide a process forpreparing hydroxylated aromatic compounds.

A further object of this invention is to provide a process forintroducing hydrogen substituents into the nucleus of an aromaticcompound utilizing certain catalystic compositions of matter to effectthe hydroxylation.

In one aspect an embodiment of this invention is found in a process forthe nuclear hydroxylation of an aromatic compound having the formula:

in which Ar is a monocyclic or polycyclic aromatic hydrocarbon nucleus,R is independently selected from the group consisting of n-alkyl,sec-alkyl, tert-alkyl, cycloalkyl, hydroxyl, alkoxyl, and hydroxy alkyl,X is selected from the group consisting of halogen and nitro, m is l or2 and n is or 1, which process comprises treating said aromatic compoundwith an aqueto hydrogen peroxide being in the range from about 3:1 toabout 15:1, in the presence of a phthalocyanine catalyst selected fromthe group consisting of metal phthalocyanines, their sulfonated andcarboxylated derivatives thereof, said metals being selected from thegroup consisting of cobalt, vanadium, manganese, iron, copper, nickel,molybdenum, chromium, and tungsten, and recovering the resultanthydroxylated aromatic compound.

A specific embodiment of this invention resides in a process for thenuclear hydroxylation of phenol which comprises treating phenol withhydrogen peroxide at a temperature in the range of from about l0 toabout C. and a pressure in the range of from about atmospheric to about50 atmospheres in the presence of a a catalyst comprising cobaltphthalocyanine disulfonate, and recovering the catechol andhydroquinone.

Other objects and embodiments of this invention will be found in thefollowing further detailed description thereof.

As hereinbefore set forth, the present invention is concerned with aprocess for introducing hydroxyl substituents into the ring of anaromatic compound, said hydroxylation being effected by treating anaromatic compound with hydrogen peroxide in the presence of certaincatalytic compositions of matter comprising metal derivatives ofphthalocyanine. The starting materials which may be utilized in theprocess of this invention comprise aromatic hydrocarbons and derivativesthereof. The term aromatic compound as used in the present specificationand appended claims will refer to these hydrocarbons and derivativesthereof and will include primary, secondary, and tertiary substitutedalkyl aromatic hydrocarbons such as toluene, o-xylene, m-xylene,p-xylene, ethylbenzene, n-propylbenzene, n-butylbenzene,n-pentylbenzene, cumene (isopropylbenzene), sec-butylbenzene,tert-butylbenzene, tert-pentylbenzene, etc., cyclopentylbenzene,cyclohexylbenzene, l-methylnaphthalene, 2-methylnaphthalene,l-ethylnaphthalene, Z-ethylnaphthalene, l-isopropylnaphthalene,2-isopropylnaphthalene, 1- tert-butylnaphthalene,2-tert-butylnapthalene, 1,2- dimethylnaphthalene,1,2-diethylnaphthalene, methylbiphenyl, ethylbiphenyl, etc.;hydroxy-substituted aromatic compounds such as phenol, hydroquinone,catechol, resorcinol, l-hydroxynaphthalene, 2-hydroxynaphthalene,1,2-dihydroxynapthalene, etc.; alkoxysubstituted aromatic compounds suchas anisole,

phenetol, n-propoxybenzene, o-methylanisole, mmethylanisole,p-methylanisole, m-ethylanisole, pethylanisole, o-methylphenetol,m-rnethylphenetol, pmethylphenetol, etc.; halo-alkyl aromatic compoundssuch as o-chlorotoluene, m-chlorotoluene, pchlorotoluene,o-bromotoluene, m-bromotoluene, pbromotoluene, o-chloroethylbenzene,m-chloroethylbenzene, p-chloroethylbenzene, o-bromoethylbenzene,m-bromoethylbenzene, p-bromoethylbenzene, 2- chlorol methylnaphthalene,2-bromol rnethylnaphthalene, 4-chloro-lmethylnaphthalene, 4-bromolmethylnaphthalene, 2-chlorol ethylnaphthalene 4-bromo-l-ethylnaphthalene, etc.; aromatic carbohydrate derivatives ofaromatic compounds such as 1 l diphenyl- 1 desoxy-D-glucitol, l ,1ditolyll desoxy- D-glucitol, l l -bis-( p-isopropylphenyl)- l desoxy-D-glucitol, l ,1-bis-(p-methoxyphenyl)-ldesoxy-D-glucitol, l, 1 -bis(p-hydroxyphenyD- l desoxy-D-glucitol, the corresponding aromaticderivatives of other hexoses (fructose, sorbose, tagatose, psicose,idose, gulose, talose), glycolaldehyde, trioses, tetraoses, pentoses,etc. It is to be understood that the aforementioned compounds are onlyrepresentative of the type of aromatic hydrocarbons and derivativesthereof which may be utilized as starting materials in the hydroxylationprocess of the present invention and that said invention is notnecessarily limited thereto.

Utilizable aromatic derivatives may be represented by the followinggeneric formula:

in which Ar is a monocyclic or polycyclic aromatic hydrocarbon nucleus,R is independently selected from the group consisting of n-alkyl,sec-alkyl, tert-alkyl, cycloalkyl, hydroxyl, alkoxyl and hydroxy-alkylradicals, X is independently selected from the group consisting ofhydrogen, halogen and nitro substituents, and m and n are integers of atleast 1.

It is also contemplated within the scope of this invention thatheterocyclic compounds such as quinoline may be treated with hydrogenperoxide in the presence of hydrogen fluoride according to the processof this invention. While the aforementioned list of compounds disclosesthe presence of primary, secondary, and tertiary alkylated aromatichydrocarbons as well as hydroxy and alkoxy substituted aromaticcompounds, it has been found that unalkylated benzene derivativesincluding benzene, halobenzenes such as chlorobenzene, bromobenzene,etc., nitrobenzenes, etc., will usually react less substantially thanthe corresponding alkylated or hydroxylated derivatives and will yield adifficulty separatable mixture of polyhydroxy aromatic compounds andother derivatives thereof.

The process of this invention is effected by treating an aromaticcompound of the type hereinbefore set forth in greater detail withhydrogen peroxide in the presence of a catalyst comprising a metalderivative of a phthalocyanine. The hydrogen peroxide may be present inan aqueous solution containing from about 5 up to about 90 percent ormore hydrogen peroxide. The preferred hydrogen peroxide solution willcontain from about 30 to about 50 percent or higher concentrations ofhydrogen peroxide inasmuch as when utilizing a lesser amount, theaqueous portion of the solution will tend to effect the recovery of thedesired product by making said recovery more difficult. Thehydroxylation conditions under which the present process of treating anaromatic compound with hydrogen peroxide is effected will includetemperatures ranging from l0 up to about 100 C. or more, the preferredtemperatures being those in a range of from ambient (about 25 C.) toabout 75 C. In addition, the reaction pressure which is utilized willpreferably be atmospheric in nature, although it is contemplated thatsomewhat higher pressures up to about 50 atmospheres may be used, thepressure being that which is necessary to maintain a substantial portionof the reactants in the liquid phase. When superatrnospheric pressuresare utilized, the pressures will be provided for by the introduction ofa substantially inert gas such as nitrogen into the reaction zone.

a metal phthalocyanine. Particularly preferred metal phthalocyaninesinclude cobalt phthalocyanine and vanadium phthalocyanine. Other metalphthalocyanines which may be utilized as catalysts in the presence ofthis invention will include manganese phthalocyanine, ironphthalocyanine, copper phthalocyanine, nickel phthalocyanine, molybdenumphthalocyanine, chromium phthalocyanine, tungsten phthalocyanine, etc.However, in most cases a derivative of a phthalocyanine is preferred, aparticularly preferred derivative being a sulfonate derivative. Thus, aparticularly preferred phthalocyanine catalyst is cobalt phthalocyaninedisulfonate. However, for increased solubility in neutral and acidicsolutions, the trisulfonate or tetrasulfonate is preferred. It isunderstood that the disulfonate or mixtures of the diand trisulfonates,as well as more highly sulfonated derivatives including, for example,cobalt phthalocyanine tetrasulfonate, may be used. Thus, the preferredcompounds for use in the present invention comprise cobaltphthalocyanine trisulfonate, cobalt phthalocyanine tetrasulfonate,vanadium phthalocyanine trisulfonate, vanadium phthalocyaninetetrasulfonate, etc., or mixtures of these with the correspondingdisulfonates. These compounds may be obtained from any suitable sourceor may be prepared in any suitable manner as, for example, by reactingcobalt or vanadium phthalocyanine with 25-50 percent fuming sulfuricacid. While the sulfonic acid derivatives are preferred, it isunderstood that other suitable derivatives may be employed.

Other derivatives of the metal phthalocyanines which may be utilized ascatalysts include, in particular, the carboxylated derivatives which maybe prepared, for example, by the action of trichloroacetic acid on themetal phthalocyanine or by the action of phosgene and aluminum chloride,on the metal phthalocyanine. In the latter reaction, the acid chlorideof the metal phthalocyanine is formed, said acid chloride then beingconverted to the desired carboxylated derivative by conventional meanssuch as hydrolysis which is wellknown in the art. Some specific examplesof these carboxylated derivatives of the metal phthalocyanines willinclude cobalt phthalocyanine dicarboxylate, cobalt phthalocyaninetricarboxylate, cobalt phthalocyanine tetracarboxylate, vanadiumphthalocyanine dicarboxylate, vanadium Phthalocyanine tricarboxylate,vanadium tetracarboxylate, manganese phthalocyanine dicarboxylate,manganese phthalocyanine tricarboxylate, manganese phthalocyaninetetracarboxylate, iron phthalocyanine dicarboxylate, iron phthalocyaninetricarboxylate, iron phthalocyanine tetracarboxylate, copperphthalocyanine dicarboxylate, copper phthalocyanine tricarboxylate,copper phthalocyanine tetracarboxylate, nickel phthalocyaninedicarboxylate, nickel phthalocyanine tricarboxylate, nickelphthalocyanine tetracarboxylate, molybdenum phthalocyaninedicarboxylate, molybdenum phthalocyanine tricarboxylate, molybdenumphthalocyanine tetracarboxylate,

chronium phthalocyanine dicarboxylate, chromium phthalocyaninetricarboxylate, chromium phthalocyanine tetracarboxylate, tungstenphthalocyanine dicarboxylate, tungsten phthalocyanine tricarboxylate,tungsten phthalocyanine tetracarboxylate, etc.

In one embodiment of the invention, the phthalo-.

cyanine catalyst is employed as an aqueous solution. In anotherembodiment the phthalocyanine catalyst is disposed on a suitable solidcarrier and utilized as a fixed bed. Any suitable carrier may beemployed. Charcoal is particularly preferred and includes, for example,bone char, wood charcoal, charcoal made from coconut or other nutshells, fruit pits, etc. Other solid carriers include alumina, silica,magnesia, thoria, zinc oxide, etc., as well as naturally occuring oressuch as bauxite, diaspore, diatomaceousearth, kaolin, kieselguhr, etc.,preferably being treated by washing, acid and/or caustic, etc., to atleast partially purify the same. The phthalocyanine catalyst may bedisposed on the solid carrier in any suitable manner including soaking,

suspending, dipping, immersing, etc., of particles of the solid carrierin a solution of the phthalocyanine catalyst or by spraying, pouring orotherwise contacting the solution of the catalyst with the solidparticles.

In yet another embodiment,the catalytic composition of matter whenutilized as a metal phthalocyanine carboxylate or phthalocyaninesulfonate may be solubilized by forming a salt of the carboxylate,polycarboxylate, sulfonate, or polysulfonate derivative. Thissolubilization of the metal phthalocyanine complex is effected utilizingan amine of preferably an amine containing from six to 20 carbon atoms.Some specific examples of these alkyl amines include hexyl amine, heptylamine, octyl amine, nonyl amine, decyl amine, undecyl amine, dodecylamine, tridecyl amine, tetradecyl amine, pentadecyl amine, hexadecylamine, heptadecyl amine, octadecyl amine, nonadecyl amine, eicosylamine, the alkyl chains of the amine being either normal or branchedchain in configuration.

It is also contemplated within the scope of this invention that thearomatic compound which is treated with hydrogen peroxide to undergonuclear hydroxylation thereof may have this hydroxylation reactioneffected in the presence of catalytic compositions of matter which maybe described as metal porphyrins, the particularly preferred porphyrincatalysts are cobalt porphyrin and vanadium porphyrin. Other metalporphyrins which may be used include iron prophyrin,manganese porphyrin,chromium porphyrin, magnesium porphyrin, copper porphyrin, nickelporphyrin, zinc porphyrin, titanium porphyrin, tin porphyrin, leadprophyrin, tantalum porphyrin, antimony porphyrin, bismuthporphyrin,molybdenum porphyrin, palladium porphyrin, platinum porphyrin,silver porphyrin, mercury porphyrin, etc., although not necessarily withthe equivalents results.

The amount of aromatic compound which is treated with the hydrogenperoxide in the presence of a metal derivative of a phthalocyanine willdetermine whether a mono-hydroxylated aromatic compound or apolyhydroxylated compound will be obtained. For example, if amono-hydroxylated aromatic compound is desired, an excess of thisreactant, namely, the aromatic compound, will be used. Converselyspeaking, if a polyhydroxylated aromatic compound is to be the desiredproduct, the relative amount of hydrogen peroxide which is used to treatthe aromatic compound will be increased. Generally speaking, thearomatic compound will be in a mo] ratio in a range of from about 3:1 toabout 15:1 mols of aromatic compound per mol of hydrogen peroxide,although greater or lesser amounts of aromatic compound may also beused, the amount which is used depending, as hereinbefore set forth, asto whether the desired product is to, be mono-hydroxylated orpolyhydroxylated.

The process of the present invention which comprises the preparation ofa hydroxylated aromatic compound'may be effected in either a continuousor batch type operation. For example, when a batch type operation isused, a quantity of the aromatic compound is placed inan appropriateapparatus such as a flask which is provided with cooling or heatingmeans, stirring means, etc., or an autoclave, along with the catalystcomprising the metal derivative of a phthalo cyanine. The hydrogenperoxide is added thereto over a relativelylong period of time, theaddition usually being accomplished by adding the hydrogen peroxidedropwise while maintaining the apparatus at the proper operatingconditions of temperature and pressure. Upon completion of the additionof the hydrogen peroxide reactant, the reaction is allowed to proceedfor a predetermined residence time, said residence time varying fromabout 0.5 up to about 5 hours or more in duration. Upon completion ofthe desired residence time, the reaction product is recovered, separatedfrom the catalyst, which may be in liquid or solid form, and subjectedto conventional means of purification and recovery, said means includingwashing the product with an inert organic solvent, flashing off thesolvent and subjecting the reaction product to fractional distillationin order to recover the desired hydroxylated aromatic compound.

It is also contemplated within the scope of this invention that theprocess for obtaining a hydroxylated aromatic compound may be effectedin a continuous manner of operation. When such a type of operation isused, the aromatic compound which is to undergo hydroxylation iscontinuously charged to a reaction zone which is maintained at theproper operating conditions of temperature and pressure, said reactionzone also containing the catalyst comprising the metal derivative of aphthalocyanine. In addition, the hydrogen peroxide in the form of anaqueous solution containing from 5 up to about percent or more hydrogenperoxide is continuously charged to the reac tion zone in a slow anddeliberate manner. The reaction is allowed to proceed for apredetermined residence time, following which the reactor effluent iscontinuously withdrawn. The reaction product is separated from theunreacted aromatic compound by conventional means and recovered, theunreacted aromatic compound then being recycled to form a portion of thefeed stock. When the catalyst comprising a metal derivative ofphthalocyanine is in solid form, the aromatic compound and the hydrogenperoxide may be passed through the catalyst which is positioned as afixed bed in the reaction zone. Alternatively speaking, the reaction mayalso be effected in a moving bed typeof operation in which the catalystand the reactants pass through the reaction zone either concurrently orlOlOS4 countercurrently to each other. In the preferred embodiment ofthe invention, the metal derivative of the phthalocyanine is utilized ininsoluble form rather than in soluble form.

Examples of hydroxylated aromatic compounds which may be preparedaccording to the process of this invention include o-hydroxytoluene(o-cresol), phydroxytoluene (p-cresol), Z-hydroxy-p-xylene, 4-hydroxy-o-xylcne, Z-hydroxyethylbenzene (oethylphenol),2,4-dihydroxyethylbenzene, Z-hydroxyp-cumene,Z-hydroxy-l-methylnaphthalene, 2,4- dihydroxy- 1 -methylnaphthalenel-hydroxy-2-methylnaphthalene, l,4-dihydroxy-2-methylnaphthalene, 2-hydroxy-l-methylanthracene, 2,4-dihydroxy-1- methylanthracene, catechol,hydroquinone, resorcinol, hydroxyhydroquinone, pyrogallol, guaiacol,2-hydroxyphenetol, 2,4-dihydroxyanisole, 2,4-dihydroxyphenetol,2-hydroxy-p-methylanisole,2-hydroxy-pethylanisole,2-hydroxy-o-chlorotoluene, Z-hydroxy-obromotoluene,4-hydroxy-o-chlorotoluene, 4-hydroxyo-bromotoluene,5-hydroxy-o-chlorotoluene, 5- hydroxy-o-bromotoluene, l,1-di-(p-hydroxyphenyl)-1- desoxy-D-glucitol, 1 1 -di-(p-hydroxyphenyl)- l -desoxy- D-mannitol, etc. It is to be understoodthat the aforementioned compounds are only representative of the classof hydroxylated aromatic compounds which may be prepared and that thepresent invention is not necessarily limited thereto.

The following examples are given to illustrate the process of thepresent invention which, however, are not intended to limit thegenerally broad scope of the present invention in strict accordancetherewith.

EXAMPLE I In this example a solution of 50 cc. of water, 14.1 g. (0.15mol) of phenol, and 0.3 g. of cobalt phthalocyanine disulfonate wasplaced in a flask provided with stirring means. The flask was vigorouslystirred at room temperature while 1 1.3 g. (0.1 mol) of percent hydrogenperoxide solution was slowly added dropwise over a period of 0.5 hours.Upon completion of the addition of the hydrogen peroxide, the solutionwas stirred for an additional period of 1 hour. At the end of this time,the reaction product was recovered, separated from the aqueous layer andthe catalyst, and subjected to analysis. There was obtained a 32 percentyield of polyhydroxylated benzene comprising catechol and hydroquinone,said yield being based on the hydrogen peroxide which was charged to thereactor.

EXAMPLE II A solution of 50 cc. of water and 16.2 g. (0.15 mol) ofanisole is placed in a flask provided with heating and stirring means,said flask also containing 0.3 g. of a catalyst comprising vanadiumphthalocyanine disulfonate. To this solution is added 1 1.3 g. (0.1 mol)of a 30 percent hydrogen peroxide solution, said solution being addeddropwise during a period of 0.5 hours. At the end of this additionperiod, the contents of the flask are stirred for an additional periodof 1 hour. At the end of this time, the reaction product is recoveredfrom the vessel, the reaction mixture is separated from the catalyst andwater and subjected to fractional distillation under reduced pressure.The desired product comprising o-methoxyphenol and p-methoxyphenol isrecovered.

EXAMPLE m In this experiment, 53 g. (0.5 mol) of ethylbenzene along with50 cc. of water and 0.3 g. of a cobalt phthalocyanine disulfonatecatalyst is placed in an apparatus provided with heating and stirringmeans. The apparatus is heated to a temperature of about 60 C. andmaintained thereat while- 6.8 g. (0.1 mol) of 50 percent hydrogenperoxide solution is slowly added thereto in a dropwise manner, theaddition being accompanied by vigorous stirring of the mixture. Afterthe addition of the hydrogen peroxide is completed, said addition beingaccomplished during a period of 0.5 hour, heating is discontinued andthe apparatus and contents thereof are allowed to return to roomtemperature, the contents being vigorously stirred for an additionalperiod of 1 hour. At the end of this time, the reaction mixture isrecovered, the product is separated from unreacted ethylbenzene, water,and catalyst, and recovered. Analysis of the desired product willdisclose the presence of ethylphenol, ethylcatechol andethylhydroquinone.

EXAMPLE IV In this example 53 g. (0.5 mol) of m-xylene, cc. of water,and 0.6 g. of a catalyst comprising vanadium phthalocyanine disulfonateis placed in a flask provided with stirring means. To this flask isadded 6.8 g. (0.1 mol) of a 50 percent hydrogen peroxide solution, theaddition of the hydrogen peroxide being effected dropwise over a periodof 0.5 hour. The contents of the flask are vigorously stirred during theaddition of the hydrogen peroxide and for an additional period of 2hours. At the end of this time, the reaction mixture is recovered. Theproduct is separated from unreacted mxylene, water and catalyst.Analysis of the desired product will disclose the presence of2,4-xylenol and 2,6-xylenol.

EXAMPLE V To a mixture of 92 g. (1.0 mol) of toluene, 100 cc. of water,and 0.6 g. of cobalt phthalocyanine disulfonate is added 13.6 g. (0.2mol) of a 50 percent hydrogen peroxide solution, the addition of thehydrogen peroxide being effected dropwise during a period of 0.5 hour.Upon completion of the addition of the hydrogen peroxide, the mixture iscontinued to be stirred for an additional period of 2 hours. Followingthis, the reac tion mixture is recovered and the product is separatedfrom water, the unreacted toluene, and catalyst. Analysis of the productby means of an infra-red apparatus will disclose the presence of amixture of cresols.

EXAMPLE Vl is slowly added dropwise over a period of 0.5 hours.-

Upon completion of the addition of the hydrogen peroxide, the solutionin the flask is stirred for an additional period of 1 hour. At the endof this time, the reaction mixture is recovered, separated from theaqueous layer and the catalyst is subjected to fractional distillationunder reduced pressure. The desired product comprising a mixture ofcatechol and hydroquinone is recovered therefrom.

EXAMPLE VII In this example 0.5 g. of manganese phthalocyaninedisulfonate is solubilized by admixing with 0.3 g. of ndecyl amine. Thesolution is then-added to 18.8 g. (0.2 mol) of phenol in a glass flaskprovided with heating and stirring means. The solution in the flask isvigorously stirred at room temperature, while 0.2 mols of a 30 percenthydrogen peroxide is added dropwise during a period of 0.5 hours. At theend of the addition time, the contents of the flask are stirred for anadditional period of 1 hour. Following the completion of thepredetermined residence time, the reaction product is recovered from thevessel, separated from the catalyst and subjected to fractionaldistillation under reduced pressure whereby the desired productcomprising catechol and hydroquinone is recovered therefrom.

EXAMPLE VIII A charge stock comprising 16.2 g. (0.15 mol) of anisole isplaced in a flask provided with heating and stirring means. In addition,a catalyst comprising 0.5 g. of cobalt phthalocyanine tetracarboxylatewhich has been solubilized in 1.2 g. of n-dodecylamine is also addedthereto. The solution is vigorously stirred while adding 11.3 g. (0.1mol) of a 30 percent hydrogen peroxide solution, the addition of thehydrogen peroxide being accomplished by a dropwise addition during aperiod of 0.5 hours. At the end of the hydrogen peroxide additionperiod, the solution is stirred for an additional 1 hour. Thereafter thereaction mixture is recovered from the vessel, the product is separatedfrom the catalyst and subjected to fractional distillation under reducedpressure whereby the desired product comprising o-methoxyphenol andp-methoxyphenol are recovered.

1 claim as my invention:

1. A process for the nuclear hydroxylation of an aromatic compoundhaving the formula:

in which Ar is a monocyclic or polycyclic aromatic hydrocarbon nucleus,R is independently selected from the group consisting of n-alkyl,sec-alkyl, tert-alkyl, cycloalkyl, hydroxyl, alkoxyl, and hydroxy alkyl,X is selected from the group consisting of halogen and nitro, m is 1 or2 and n is 0 or 1, which process comprises treating said aromaticcompound with an aqueous hydrogen peroxide containing from about 5 toabout percent hydrogen peroxide, at a temperature of from about l0 toabout C. and a pressure of from atmospheric to about 50 atmospheressufficient to maintain a substantial portion of the reactants in theliquid phase, the mol ratio of said aromatic compound to hydrogenperoxide being in the range of from about 3:1 to about 15:1, in thepresence of a phthalocyanine catalyst selected from the group consistingof metal phthalocyanines, their sulfonated and carboxylated derivativesthereof, said metals being selected from the group consisting of cobalt,vanadium, manganese, iron, copper, nickel, molybdenum, chromium, andtungsten,

and recovering the resultant hydroxylated aromatic compound.

2. The process as set forth in claim 1 in which said hydroxylationconditions include a temperature in the range of from l0 to about 100 C.and a pressure in the range of from atmospheric to about 50 atmospheres.

3. The process as set forth in claim 1 in which catalyst is manganesephthalocyanine.

4. The process as set forth in claim 1 in which said catalyst comprisescobalt phthalocyanine disulfonate.

5. The process as set forth in claim 1 in which said catalyst comprisesvanadium phthalocyanine disulfonate.

6. The process as set forth in claim 1 in which said catalyst ismanganese phthalocyanine dicarboxylate.

7. The process as set forth in claim 1 in which said aromatic compoundis phenol and said hydroxylated aromatic compound is a mixture ofcatechol and hydroquinone.

8. The process as set forth in claim 1 in which said aromatic compoundis toluene and said hydroxylated aromatic compound is a mixture ofcresols.

9. The process as set forth in claim 1 in which said aromatic compoundis anisole and said hydroxylated aromatic compound is a mixture ofo-methoxyphenol and p-methoxyphenol.

10. The process as set forth in claim 1 in which said aromatic compoundis m-xylene and said hydroxylated aromatic compound is a mixture of2,4-xylenol and 2,6- xylenol.

11. The process as set forth in claim 1 in which said aromatic compoundis ethylbenzene and said hydroxylated aromatic compound is a mixture ofethylphenol, ethylcatechol, and ethylhydroquinone.

2. The process as set forth in claim 1 in which said hydroxylation conditions include a temperature in the range of from -10* to about 100* C. and a pressure in the range of from atmospheric to about 50 atmospheres.
 3. The process as set forth in claim 1 in which catalyst is manganese phthalocyanine.
 4. The process as set forth in claim 1 in which said catalyst comprises cobalt phthalocyanine disulfonate.
 5. The process as set forth in claim 1 in which said catalyst comprises vanadium phthalocyanine disulfonate.
 6. The process as set forth in claim 1 in which said catalyst is manganese phthalocyanine dicarboxylate.
 7. The process as set forth in claim 1 in which said aromatic compound is phenol and said hydroxylated aromatIc compound is a mixture of catechol and hydroquinone.
 8. The process as set forth in claim 1 in which said aromatic compound is toluene and said hydroxylated aromatic compound is a mixture of cresols.
 9. The process as set forth in claim 1 in which said aromatic compound is anisole and said hydroxylated aromatic compound is a mixture of o-methoxyphenol and p-methoxyphenol.
 10. The process as set forth in claim 1 in which said aromatic compound is m-xylene and said hydroxylated aromatic compound is a mixture of 2,4-xylenol and 2,6-xylenol.
 11. The process as set forth in claim 1 in which said aromatic compound is ethylbenzene and said hydroxylated aromatic compound is a mixture of ethylphenol, ethylcatechol, and ethylhydroquinone. 